Kevin Siembieda’s Rifts is the latest tabletop RPG with a Bundle of Holding offering. What’s the deal? US$17.95 unlocks the full starter collection as DRM-free ebooks. That means the Rifts Ultimate Edition (normally $20), Rifts Primer ($3), Rifts Sourcebook One Revised Edition ($10.50), Game Master Kit ($5) and the 360-paged Game Master Guide ($13.50).…